One example of conventional lenses for glasses protecting from laser beams is disclosed in the Japanese Patent Application published in the official gazette under 54-27451A (page 1), in which a colored glass is used as a filter, the glass having optical characteristics to restrain a transmission amount of a laser beam relating to an oscillation wavelength light of an oscillated laser beam to a tolerable transmission amount with respect to human eyes and highly transmitting the other wavelength lights.
Another example of lenses protecting from laser beam is disclosed in the Japanese Patent Application published in the official gazette under 62-231952A (page 1), in which at least one side of a plastic lens containing an absorption substance with a laser oscillation wavelength range in an absorption band has a lamination of high refractive index layers and low refractive index layers alternately(m=0 or 1), the lamination having an optical thickness of (2m+1)λ/4 (m=0, 1; λ=laser oscillation wavelength).
Moreover, one example of lenses for polarizing glasses is disclosed in Japanese Patent Application in the official gazette under 6-67125A (page 1). This lens includes a plurality of translucent materials having different refractive indices on a interface, and the interface has an inclined surface and the surface has a plurality of wave shapes in cross-section, the waves are provided adjacent to each other in one direction.
Furthermore, another example of lenses for polarizing glasses is disclosed in the Japanese Patent Application in the official gazette under 2001-350122A (page 1). This lens includes a first lens element made of an inorganic glass, a thermoplastic synthetic resin or a thermosetting synthetic resin, a second lens element made of a thermoplastic synthetic resin or a thermosetting synthetic resin, and a polarizing film. The production method thereof includes a step of attaching and affixing the first and second lens elements in a manner that the polarizing film stands between the elements.
Patent Document 1: the official gazette, No. 54-27451A (page 1)
Patent Document 2: the official gazette, No. 62-231925A (page 1)
Patent Document 3: the official gazette, No. 6-67125A (page 1)
Patent Document 4: the official gazette, No. 2001-350122A (page 1)